This invention relates to rapamycin derivatives, pharmaceutical compositions comprising such derivatives, and methods of treatment of pathogenic fungi, methods of inducing immunosuppression and methods of treating carcinogenic tumors utilizing such rapamycin derivatives.
Rapamycin is a naturally occurring macrocyclic triene antibiotic which can be produced by culturing an organism in an aqueous nutrient medium. Its structure may be illustrated as follows: ##STR1##
At least one rapamycin-producing strain of Streptomyces hygroscopius was deposited with the Northern Utilization and Research Division, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Ill., U.S.A. under accession number NRRL 5491. Rapamycin, and methods for its preparation by culturing NRRL 5491 are disclosed by U.S. Pat. No. 3,929,992, issued Dec. 30, 1975, the entire disclosure of which is hereby incorporated by reference.